Judge Amy Berman Jackson sharply challenged the department’s claim that federal courts have no jurisdiction in the dispute. Department lawyer Ian Gershengorn said the battle over the documents should be resolved by the checks and balances between the legislative and executive branches.

“I’m a check and balance,” countered Jackson, an appointee of President Barack Obama. “The third branch exists.”

The House Oversight and Government Reform Committee is seeking documents that might explain what led the Justice Department to reverse course after initially denying that federal agents had used a tactic called “gun-walking” in the law enforcement operation.

Obama has invoked executive privilege and Attorney General Eric Holder has been found to be in contempt of Congress for refusing to turn over the documents sought. The GOP-led House sued to get the records.

The department has turned over thousands of pages of material on the operation itself. The continuing dispute is over documents describing how the department responded once Congress started investigating.

Gershengorn said that if the suit were dismissed, Congress had other powers at its disposal, such as the power of the purse. He said that negotiations and accommodation between the House and the executive branch are messy and contentious, but that the system allows for accountability with voters.

He argued that that process was distorted by the House’s lawsuit, and that there was a danger of courts becoming “a tool of the political process.”

Jackson questioned why an impartial third party wouldn’t help, rather than hinder, negotiations. She also noted that she delayed an earlier hearing so the two sides could try to work out an agreement through mediation, but those efforts failed.

“If you could have worked this out yourselves, wouldn’t you have worked this out yourselves?” she asked.

House lawyer Kerry Kircher called the notion that there haven’t been meaningful negotiations and accommodations “preposterous.”

“We’ve been negotiating for four months,” Kircher said.

He also said the House was at a disadvantage.

“This is an asymmetrical relationship here,” Kircher said. “They have the documents. We don’t have the documents.”

As to Congress’ powers, such as reducing spending for the executive branch, he said, “All that means is they get less money” — not that the committee gets the documents.

Fast and Furious was a flawed gun-tracking investigation focused on Phoenix-area gun shops by the Justice Department’s Bureau of Alcohol, Tobacco, Firearms and Explosives. Agents lost track of about 1,400 guns, and two guns in Operation Fast and Furious were found on the U.S. side of the border at the scene of a shooting in which U.S. border agent Brian Terry was killed.